In general, a display device refers to monitors for a TV or a computer as a whole, and comprises a display device forming an image and a case supporting the display device.
Examples of the display device may comprise a plasma display panel (PDP), a liquid crystal display (LCD), an electrophoretic display, and a cathode-ray tube (CRT). An RGB pixel pattern for implementing an image and an additional optical filter may be provided in the display device.
The optical filter may comprise at least one of a reflection prevention film preventing the light that is incident from the outside from being reflected to the outside, a near IR shield film shielding the near IR generated in the display device in order to prevent mis-operation of electronic devices such as remote controllers, a color correction film increasing the color purity by controlling a color tone by comprising a color control dye, and an electromagnetic wave shield film shielding the electromagnetic wave generated in a display device when a display apparatus is driven. Here, the electromagnetic wave shield film comprises a transparent substrate and a metal mesh pattern provided on the substrate.
Meanwhile, with regard to the display apparatus, as the spread of IPTVs is accelerated, a demand for a touch function that uses hands as a direct input apparatus without a separate input apparatus such as remote controllers is growing. In addition, a multi-touch function for recognizing a specific point and taking notes is required.
The touch panel performing the aforementioned function may be classified into the following types according to detection manner of a signal.
That is, examples thereof comprise a resistive type detecting a position pressed by pressure in a state where a direct voltage is applied while changing a current or voltage value, a capacitive type using capacitance coupling in a state where an alternating voltage is applied, an electromagnetic type detecting a selected position in a state where a magnetic field is applied as a change in voltage, and the like.
Among them, the resistive type and capacitive type touch panels that are most extensively spread recognize the touch by a change in electric contact or capacitance by using the transparent conductive film such as the ITO film. However, since the transparent conductive film has high resistance of 100 ohms/square or more, the sensitivity is lowered when the display device is manufactured in a large scale, and as the size of screen is increased, the cost of the ITO film is rapidly increased, accordingly, it is not easy to perform commercialization thereof. In order to overcome this, there is an effort to implement enlargement by using a metal pattern having high conductivity.
In the case of a known transparent conductor comprising ITO and a transparent conductor comprising a conductive pattern and a metal line, a dummy pattern for implementing uniform transmittance on one surface has been introduced, precise alignment and lamination of a metal line, a metal line between constitutional elements of each touch panel have been ensured, or the transparent conductive film on the one surface, in which line breakage is introduced within a predetermined ratio, has been implemented in order to overcome a problem of visibility according to a transmittance difference of a transparent conductive film constituting a touch panel. However, this method has problems in that a loss of transmittance occurs due to the presence of an additional region not providing a large electric affection, it is difficult to ensure precision of alignment in the case where a fine line is introduced (10 μm or less and the like), and transmittance is reduced when two transparent conductive films are laminated by maintaining a predetermined pitch and closing ratio on the one surface in order to ensure uniformity of the one surface.